Deliberate mistake: At the beginning, Asajj Ventress is wearing an outfit with a long skirt. When she is rescued from her damaged starfighter by the scavengers, the skirt has vanished. This was done because the animators found the skirt too difficult to animate. This is also why she receives a brand new outfit that never had a long skirt later in the episode.
Other mistake: During Padmé's big speech to the Senate, Duchess Satine is visible in the background watching at one point. Satine is the ruler of Mandalore, a neutral planet, not a Senator, and thus has no reason to be present at a normal session of the Galactic Senate.
New this month Plot hole: When Ahsoka rushes to save the students when they arrive to meet the prime minister, she kicks the secret service agent, however we see her standing next to the prime minister acting innocent. The agent she kicked to save the students would have no doubt told the prime minister right away that Ahsoka stopped them, and the prime minister would know which side she was on.